package org.jeecg.weixin.common.util.http;

import java.nio.charset.StandardCharsets;

import org.apache.commons.lang3.StringUtils;

public class URIUtil {

	private static final String ALLOWED_CHARS = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789-_.!~*'()";

	public static String encodeURIComponent(String input) {
		if (StringUtils.isEmpty(input)) {
			return input;
		}

		int l = input.length();
		StringBuilder o = new StringBuilder(l * 3);
		for (int i = 0; i < l; i++) {
			String e = input.substring(i, i + 1);
			if (!ALLOWED_CHARS.contains(e)) {
				byte[] b = e.getBytes(StandardCharsets.UTF_8);
				o.append(getHex(b));
				continue;
			}
			o.append(e);
		}
		return o.toString();
	}

	private static String getHex(byte[] buf) {
		StringBuilder o = new StringBuilder(buf.length * 3);
		for (byte aBuf : buf) {
			int n = aBuf & 0xff;
			o.append("%");
			if (n < 0x10) {
				o.append("0");
			}
			o.append(Long.toString(n, 16).toUpperCase());
		}
		return o.toString();
	}
}
